Descriptive Ling query

[Bethany K. Dumas]

Colleagues, one of our undergraduate Lx majors is seeking a recommended
book for her summer project. She will be spending the summer in China with
a missionary group, and she wants to research a Tibetan language and
write a paper for Independent study credit. She has had only one Lx course
_ intro to ... What single book should I recommend that she use? She plans
to describe the phonetics or other characteristics of the language.

Thanks,
Bethany